Cell markers in stored blood

Patients subjected to major injury and major operations often receive large quantities of stored blood. In units of whole blood the most common cell markers of lymphocytes were studied when the blood had been stored for 1 week. The blood was studied both before and after passing through a microfilter. The reduction in the total white blood cell count was substantially due to a decrease in the number of granulocytes. The percentage of lymphocytes forming E-rosettes was reduced from 69 to 17 per cent following 24 hours of storage, while the percentage of lymphocytes exhibiting non-specific esterase activity was not reduced after 1 week. The proportion of lymphocytes with surface-bound immunoglobulin (Ig) was increased. This increase was due to secondary Ig binding to lymphocytes carrying Fc receptors. The proportion of lymphocytes forming EA-rosettes was unaltered throughout the study. There was little loss of cells after filtration.